xnu-517.7.21.tar.gz

[apple/xnu.git] / bsd / net / if_vlan.c

/*
 * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright 1998 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that both the above copyright notice and this
 * permission notice appear in all copies, that both the above
 * copyright notice and this permission notice appear in all
 * supporting documentation, and that the name of M.I.T. not be used
 * in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  M.I.T. makes
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 * 
 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/sys/net/if_vlan.c,v 1.54 2003/10/31 18:32:08 brooks Exp $
 */

/*
 * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs.
 * Might be extended some day to also handle IEEE 802.1p priority
 * tagging.  This is sort of sneaky in the implementation, since
 * we need to pretend to be enough of an Ethernet implementation
 * to make arp work.  The way we do this is by telling everyone
 * that we are an Ethernet, and then catch the packets that
 * ether_output() left on our output queue when it calls
 * if_start(), rewrite them for use by the real outgoing interface,
 * and ask it to send them.
 */


#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/kern_event.h>

#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/if_vlan_var.h>

#include <net/dlil.h>

#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif

#include <net/if_media.h>

#define ETHER_VLAN_ENCAP_LEN    4       /* len of 802.1Q VLAN encapsulation */
#define IF_MAXUNIT      0x7fff          /* historical value */

#define IFP2AC(p) ((struct arpcom *)p)

#define VLAN_PROTO_FAMILY       0x766c616e /* 'vlan' */

#define VLANNAME        "vlan"

typedef int (bpf_callback_func)(struct ifnet *, struct mbuf *);
typedef int (if_set_bpf_tap_func)(struct ifnet *ifp, int mode, bpf_callback_func * func);

struct vlan_mc_entry {
    struct ether_addr           mc_addr;
    SLIST_ENTRY(vlan_mc_entry)  mc_entries;
};

struct  ifvlan {
    char        ifv_name[IFNAMSIZ]; /* our unique id */
    struct  ifnet *ifv_ifp;  /* our interface */
    struct      ifnet *ifv_p;   /* parent interface of this vlan */
    struct      ifv_linkmib {
        int     ifvm_parent;
        int     ifvm_encaplen;  /* encapsulation length */
        int     ifvm_mtufudge;  /* MTU fudged by this much */
        int     ifvm_mintu;     /* min transmission unit */
        u_int16_t ifvm_proto; /* encapsulation ethertype */
        u_int16_t ifvm_tag; /* tag to apply on packets leaving if */
    }   ifv_mib;
    SLIST_HEAD(__vlan_mchead, vlan_mc_entry)    vlan_mc_listhead;
    LIST_ENTRY(ifvlan) ifv_list;
    int ifv_flags;
    int ifv_detaching;
    u_long ifv_filter_id;
    int ifv_filter_valid;
    bpf_callback_func * ifv_bpf_input;
    bpf_callback_func * ifv_bpf_output;
};

#define ifv_tag ifv_mib.ifvm_tag
#define ifv_encaplen    ifv_mib.ifvm_encaplen
#define ifv_mtufudge    ifv_mib.ifvm_mtufudge
#define ifv_mintu       ifv_mib.ifvm_mintu

#define IFVF_PROMISC            0x01            /* promiscuous mode enabled */

#if 0
SYSCTL_DECL(_net_link);
SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW, 0, "IEEE 802.1Q VLAN");
SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0, "for consistency");
#endif 0

#define M_VLAN          M_DEVBUF

MALLOC_DEFINE(M_VLAN, VLANNAME, "802.1Q Virtual LAN Interface");

static LIST_HEAD(, ifvlan) ifv_list;

#if 0
/*
 * Locking: one lock is used to guard both the ifv_list and modification
 * to vlan data structures.  We are rather conservative here; probably
 * more than necessary.
 */
static struct mtx ifv_mtx;
#define VLAN_LOCK_INIT()        mtx_init(&ifv_mtx, VLANNAME, NULL, MTX_DEF)
#define VLAN_LOCK_DESTROY()     mtx_destroy(&ifv_mtx)
#define VLAN_LOCK_ASSERT()      mtx_assert(&ifv_mtx, MA_OWNED)
#define VLAN_LOCK()     mtx_lock(&ifv_mtx)
#define VLAN_UNLOCK()   mtx_unlock(&ifv_mtx)
#else
#define VLAN_LOCK_INIT()
#define VLAN_LOCK_DESTROY()
#define VLAN_LOCK_ASSERT()
#define VLAN_LOCK()
#define VLAN_UNLOCK()
#endif 0

static  int vlan_clone_create(struct if_clone *, int);
static  void vlan_clone_destroy(struct ifnet *);
static  int vlan_output(struct ifnet *ifp, struct mbuf *m);
static  void vlan_ifinit(void *foo);
static  int vlan_ioctl(struct ifnet *ifp, u_long cmd, void * addr);
static  int vlan_set_bpf_tap(struct ifnet * ifp, int mode,
                             bpf_callback_func * func);
static  int vlan_attach_protocol(struct ifnet *ifp);
static  int vlan_detach_protocol(struct ifnet *ifp);
static  int vlan_attach_filter(struct ifnet * ifp, u_long * filter_id);
static  int vlan_detach_filter(u_long filter_id);
static  int vlan_setmulti(struct ifnet *ifp);
static  int vlan_unconfig(struct ifnet *ifp);
static  int vlan_config(struct ifvlan *ifv, struct ifnet *p, int tag);
static  int vlan_if_free(struct ifnet * ifp);

static struct if_clone vlan_cloner = IF_CLONE_INITIALIZER(VLANNAME,
                                                          vlan_clone_create, vlan_clone_destroy, 0, IF_MAXUNIT);

static  if_set_bpf_tap_func nop_if_bpf;
static  int nop_if_free(struct ifnet *);
static  int nop_if_ioctl(struct ifnet *, u_long, void *);
static  int nop_if_output(struct ifnet * ifp, struct mbuf * m);

static  void interface_link_event(struct ifnet * ifp, u_long event_code);

static __inline__ void 
vlan_bpf_output(struct ifnet * ifp, struct mbuf * m, 
                bpf_callback_func func)
{
    if (func != NULL) {
        func(ifp, m);
    }
    return;
}

static __inline__ void 
vlan_bpf_input(struct ifnet * ifp, struct mbuf * m, 
               bpf_callback_func func, char * frame_header,
               int frame_header_len, int encap_len)
{
    if (func != NULL) {
        if (encap_len > 0) {
            /* present the right header to bpf */
            bcopy(frame_header, frame_header + encap_len, frame_header_len);
        }
        m->m_data -= frame_header_len;
        m->m_len += frame_header_len;
        func(ifp, m);
        m->m_data += frame_header_len;
        m->m_len -= frame_header_len;
        if (encap_len > 0) {
            /* restore the header */
            bcopy(frame_header + encap_len, frame_header, frame_header_len);
        }
    }
    return;
}

static struct ifaddr * 
ifaddr_byindex(unsigned int i)
{
    if (i > if_index || i == 0) {
        return (NULL);
    }
    return (ifnet_addrs[i - 1]);
}

/*
 * Program our multicast filter. What we're actually doing is
 * programming the multicast filter of the parent. This has the
 * side effect of causing the parent interface to receive multicast
 * traffic that it doesn't really want, which ends up being discarded
 * later by the upper protocol layers. Unfortunately, there's no way
 * to avoid this: there really is only one physical interface.
 */
static int
vlan_setmulti(struct ifnet *ifp)
{
    struct ifnet                *p;
    struct ifmultiaddr  *ifma, *rifma = NULL;
    struct ifvlan               *sc;
    struct vlan_mc_entry        *mc = NULL;
    struct sockaddr_dl  sdl;
    int                 error;

    /* Find the parent. */
    sc = ifp->if_private;
    p = sc->ifv_p;
    if (p == NULL) {
        /* no parent, so no need to program the multicast filter */
        return (0);
    }

    bzero((char *)&sdl, sizeof sdl);
    sdl.sdl_len = sizeof sdl;
    sdl.sdl_family = AF_LINK;
    sdl.sdl_index = p->if_index;
    sdl.sdl_type = IFT_ETHER;
    sdl.sdl_alen = ETHER_ADDR_LEN;

    /* First, remove any existing filter entries. */
    while (SLIST_FIRST(&sc->vlan_mc_listhead) != NULL) {
        mc = SLIST_FIRST(&sc->vlan_mc_listhead);
        bcopy((char *)&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN);
        error = if_delmulti(p, (struct sockaddr *)&sdl);
        if (error)
            return(error);
        SLIST_REMOVE_HEAD(&sc->vlan_mc_listhead, mc_entries);
        FREE(mc, M_VLAN);
    }

    /* Now program new ones. */
    LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
        if (ifma->ifma_addr->sa_family != AF_LINK)
            continue;
        mc = _MALLOC(sizeof(struct vlan_mc_entry), M_VLAN, M_WAITOK);
        bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
              (char *)&mc->mc_addr, ETHER_ADDR_LEN);
        SLIST_INSERT_HEAD(&sc->vlan_mc_listhead, mc, mc_entries);
        bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
              LLADDR(&sdl), ETHER_ADDR_LEN);
        error = if_addmulti(p, (struct sockaddr *)&sdl, &rifma);
        if (error)
            return(error);
    }

    return(0);
}

#if 0
/*
 * VLAN support can be loaded as a module.  The only place in the
 * system that's intimately aware of this is ether_input.  We hook
 * into this code through vlan_input_p which is defined there and
 * set here.  Noone else in the system should be aware of this so
 * we use an explicit reference here.
 *
 * NB: Noone should ever need to check if vlan_input_p is null or
 *     not.  This is because interfaces have a count of the number
 *     of active vlans (if_nvlans) and this should never be bumped
 *     except by vlan_config--which is in this module so therefore
 *     the module must be loaded and vlan_input_p must be non-NULL.
 */
extern  void (*vlan_input_p)(struct ifnet *, struct mbuf *);

static int
vlan_modevent(module_t mod, int type, void *data) 
{ 

    switch (type) { 
    case MOD_LOAD: 
        LIST_INIT(&ifv_list);
        VLAN_LOCK_INIT();
        vlan_input_p = vlan_input;
        if_clone_attach(&vlan_cloner);
        break; 
    case MOD_UNLOAD: 
        if_clone_detach(&vlan_cloner);
        vlan_input_p = NULL;
        while (!LIST_EMPTY(&ifv_list))
            vlan_clone_destroy(LIST_FIRST(&ifv_list)->ifv_ifp);
        VLAN_LOCK_DESTROY();
        break;
    } 
    return 0; 
} 

static moduledata_t vlan_mod = { 
    "if_vlan", 
    vlan_modevent, 
    0
}; 

DECLARE_MODULE(if_vlan, vlan_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);

#endif 0

static struct ifvlan * 
vlan_lookup_ifp_and_tag(struct ifnet * ifp, int tag)
{
    struct ifvlan * ifv;

    LIST_FOREACH(ifv, &ifv_list, ifv_list) {
        if (ifp == ifv->ifv_p && tag == ifv->ifv_tag) {
            return (ifv);
        }
    }
    return (NULL);
}

static struct ifvlan * 
vlan_lookup_ifp(struct ifnet * ifp)
{
    struct ifvlan * ifv;

    LIST_FOREACH(ifv, &ifv_list, ifv_list) {
        if (ifp == ifv->ifv_p) {
            return (ifv);
        }
    }
    return (NULL);
}

static void
vlan_clone_attach(void)
{
    if_clone_attach(&vlan_cloner);
    return;
}

static int
vlan_clone_create(struct if_clone *ifc, int unit)
{
    int error;
    struct ifvlan *ifv;
    struct ifnet *ifp;

    ifv = _MALLOC(sizeof(struct ifvlan), M_VLAN, M_WAITOK);
    bzero(ifv, sizeof(struct ifvlan));
    SLIST_INIT(&ifv->vlan_mc_listhead);

    /* use the interface name as the unique id for ifp recycle */
    if (snprintf(ifv->ifv_name, sizeof(ifv->ifv_name), "%s%d",
                 ifc->ifc_name, unit) >= sizeof(ifv->ifv_name)) {
        FREE(ifv, M_VLAN);
        return (EINVAL);
    }
    error = dlil_if_acquire(APPLE_IF_FAM_VLAN,
                            ifv->ifv_name,
                            strlen(ifv->ifv_name),
                            &ifp);
    if (error) {
        FREE(ifv, M_VLAN);
        return (error);
    }
    ifv->ifv_ifp = ifp;
    ifp->if_private = ifv;
    ifp->if_name = (char *)ifc->ifc_name;
    ifp->if_unit = unit;
    ifp->if_family = APPLE_IF_FAM_VLAN;

#if 0
    /* NB: flags are not set here */
    ifp->if_linkmib = &ifv->ifv_mib;
    ifp->if_linkmiblen = sizeof ifv->ifv_mib;
    /* NB: mtu is not set here */
#endif 0

    ifp->if_ioctl = vlan_ioctl;
    ifp->if_set_bpf_tap = vlan_set_bpf_tap;
    ifp->if_free = nop_if_free;
    ifp->if_output = nop_if_output;
    ifp->if_hwassist = 0;
    ifp->if_addrlen = ETHER_ADDR_LEN; /* XXX ethernet specific */
    ifp->if_baudrate = 0;
    ifp->if_type = IFT_L2VLAN;
    ifp->if_hdrlen = ETHER_VLAN_ENCAP_LEN;
    error = dlil_if_attach(ifp);
    if (error) {
        dlil_if_release(ifp);
        FREE(ifv, M_VLAN);
        return (error);
    }

    /* attach as ethernet */
    bpfattach(ifp, DLT_EN10MB, sizeof(struct ether_header));

    VLAN_LOCK();
    LIST_INSERT_HEAD(&ifv_list, ifv, ifv_list);
    VLAN_UNLOCK();

    return (0);
}

static void
vlan_remove(struct ifvlan * ifv)
{
    VLAN_LOCK_ASSERT();
    ifv->ifv_detaching = 1;
    vlan_unconfig(ifv->ifv_ifp);
    LIST_REMOVE(ifv, ifv_list);
    return;
}

static void
vlan_if_detach(struct ifnet * ifp)
{
    ifp->if_output = nop_if_output;
    ifp->if_ioctl = nop_if_ioctl;
    ifp->if_set_bpf_tap = &nop_if_bpf;
    if (dlil_if_detach(ifp) == DLIL_WAIT_FOR_FREE) {
        ifp->if_free = vlan_if_free;
    } else {
        vlan_if_free(ifp);
    }
    return;
}

static void
vlan_clone_destroy(struct ifnet *ifp)
{
    struct ifvlan *ifv = ifp->if_private;

    if (ifv == NULL || ifp->if_type != IFT_L2VLAN) {
        return;
    }
    VLAN_LOCK();
    if (ifv->ifv_detaching) {
        VLAN_UNLOCK();
        return;
    }
    vlan_remove(ifv);
    VLAN_UNLOCK();
    vlan_if_detach(ifp);
    return;
}

static int 
vlan_set_bpf_tap(struct ifnet * ifp, int mode, bpf_callback_func * func)
{
    struct ifvlan *ifv = ifp->if_private;

    switch (mode) {
        case BPF_TAP_DISABLE:
            ifv->ifv_bpf_input = ifv->ifv_bpf_output = NULL;
            break;

        case BPF_TAP_INPUT:
            ifv->ifv_bpf_input = func;
            break;

        case BPF_TAP_OUTPUT:
            ifv->ifv_bpf_output = func;
            break;
        
        case BPF_TAP_INPUT_OUTPUT:
            ifv->ifv_bpf_input = ifv->ifv_bpf_output = func;
            break;
        default:
            break;
    }
    return 0;
}

static void
vlan_ifinit(void *foo)
{
    return;
}

static int
vlan_output(struct ifnet *ifp, struct mbuf *m)
{
    struct ifvlan *ifv;
    struct ifnet *p;
    struct ether_vlan_header *evl;
    int soft_vlan;

    ifv = ifp->if_private;
    p = ifv->ifv_p;
    if (p == NULL) {
        return (nop_if_output(ifp, m));
    }
    if (m == 0) {
        printf("%s: NULL output mbuf\n", ifv->ifv_name);
        return (EINVAL);
    }
    if ((m->m_flags & M_PKTHDR) == 0) {
        printf("%s: M_PKTHDR bit not set\n", ifv->ifv_name);
        m_freem(m);
        return (EINVAL);
    }
    ifp->if_obytes += m->m_pkthdr.len;
    ifp->if_opackets++;
    soft_vlan = (p->if_hwassist & IF_HWASSIST_VLAN_TAGGING) == 0;
    vlan_bpf_output(ifp, m, ifv->ifv_bpf_output);

    /* do not run parent's if_output() if the parent is not up */
    if ((p->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING)) {
        m_freem(m);
        ifp->if_collisions++;
        return (0);
    }
    /*
     * If underlying interface can do VLAN tag insertion itself,
     * just pass the packet along. However, we need some way to
     * tell the interface where the packet came from so that it
     * knows how to find the VLAN tag to use.  We use a field in
     * the mbuf header to store the VLAN tag, and a bit in the
     * csum_flags field to mark the field as valid.
     */
    if (soft_vlan == 0) {
        m->m_pkthdr.csum_flags |= CSUM_VLAN_TAG_VALID;
        m->m_pkthdr.vlan_tag = ifv->ifv_tag;
    } else {
        M_PREPEND(m, ifv->ifv_encaplen, M_DONTWAIT);
        if (m == NULL) {
            printf("%s: unable to prepend VLAN header\n", 
                   ifv->ifv_name);
            ifp->if_ierrors++;
            return (0);
        }
        /* M_PREPEND takes care of m_len, m_pkthdr.len for us */
        if (m->m_len < sizeof(*evl)) {
            m = m_pullup(m, sizeof(*evl));
            if (m == NULL) {
                printf("%s: cannot pullup VLAN header\n",
                       ifv->ifv_name);
                ifp->if_ierrors++;
                return (0);
            }
        }
                
        /*
         * Transform the Ethernet header into an Ethernet header
         * with 802.1Q encapsulation.
         */
        bcopy(mtod(m, char *) + ifv->ifv_encaplen,
              mtod(m, char *), ETHER_HDR_LEN);
        evl = mtod(m, struct ether_vlan_header *);
        evl->evl_proto = evl->evl_encap_proto;
        evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
        evl->evl_tag = htons(ifv->ifv_tag);
        m->m_pkthdr.len += ifv->ifv_encaplen;
    }
        
    /*
     * Send it, precisely as ether_output() would have.
     * We are already running at splimp.
     */
    return ((*p->if_output)(p, m));
}

extern int 
vlan_demux(struct ifnet * ifp, struct mbuf * m, 
           char * frame_header, struct if_proto * * proto)
{
    register struct ether_header *eh = (struct ether_header *)frame_header;
    struct ether_vlan_header *evl;
    struct ifvlan *ifv = NULL;
    int soft_vlan = 0;
    u_int tag;

    if (m->m_pkthdr.csum_flags & CSUM_VLAN_TAG_VALID) {
        /*
         * Packet is tagged, m contains a normal
         * Ethernet frame; the tag is stored out-of-band.
         */
        m->m_pkthdr.csum_flags &= ~CSUM_VLAN_TAG_VALID;
        tag = EVL_VLANOFTAG(m->m_pkthdr.vlan_tag);
        m->m_pkthdr.vlan_tag = 0;
    } else {
        soft_vlan = 1;

        switch (ifp->if_type) {
        case IFT_ETHER:
            if (m->m_len < ETHER_VLAN_ENCAP_LEN) {
                m_freem(m);
                return (EJUSTRETURN);
            }
            evl = (struct ether_vlan_header *)frame_header;
            if (ntohs(evl->evl_proto) == ETHERTYPE_VLAN) {
                /* don't allow VLAN within VLAN */
                m_freem(m);
                return (EJUSTRETURN);
            }
            tag = EVL_VLANOFTAG(ntohs(evl->evl_tag));

            /*
             * Restore the original ethertype.  We'll remove
             * the encapsulation after we've found the vlan
             * interface corresponding to the tag.
             */
            evl->evl_encap_proto = evl->evl_proto;
            break;
        default:
            printf("vlan_demux: unsupported if type %u", 
                   ifp->if_type);
            m_freem(m);
            return (EJUSTRETURN);
            break;
        }
    }
    if (tag != 0) {
        if (ifp->if_nvlans == 0) {
            /* don't bother looking through the VLAN list */
            m_freem(m);
            ifp->if_noproto++;
            return (EJUSTRETURN);
        }
        VLAN_LOCK();
        ifv = vlan_lookup_ifp_and_tag(ifp, tag);
        if (ifv == NULL || (ifv->ifv_ifp->if_flags & IFF_UP) == 0) {
            VLAN_UNLOCK();
            m_freem(m);
            ifp->if_noproto++;
            return (EJUSTRETURN);
        }
        VLAN_UNLOCK();          /* XXX extend below? */
    }
    if (soft_vlan) {
        /*
         * Packet had an in-line encapsulation header;
         * remove it.  The original header has already
         * been fixed up above.
         */
        m->m_len -= ETHER_VLAN_ENCAP_LEN;
        m->m_data += ETHER_VLAN_ENCAP_LEN;
        m->m_pkthdr.len -= ETHER_VLAN_ENCAP_LEN;
        m->m_pkthdr.csum_flags = 0; /* can't trust hardware checksum */
    }
    if (tag != 0) {
        /* we found a vlan interface above, so send it up */
        m->m_pkthdr.rcvif = ifv->ifv_ifp;
        ifv->ifv_ifp->if_ipackets++;
        ifv->ifv_ifp->if_ibytes += m->m_pkthdr.len;

        vlan_bpf_input(ifv->ifv_ifp, m, ifv->ifv_bpf_input, frame_header,
                       ETHER_HDR_LEN, soft_vlan ? ETHER_VLAN_ENCAP_LEN : 0);

        /* Pass it back through the parent's demux routine. */
        return ((*ifp->if_demux)(ifv->ifv_ifp, m, frame_header, proto));
    }
    /* Pass it back through calling demux routine. */
    return ((*ifp->if_demux)(ifp, m, frame_header, proto));
}

static int
vlan_config(struct ifvlan *ifv, struct ifnet *p, int tag)
{
    struct ifnet * ifp;
    struct ifaddr *ifa1, *ifa2;
    struct sockaddr_dl *sdl1, *sdl2;
    int supports_vlan_mtu = 0;

    VLAN_LOCK_ASSERT();
    if (p->if_data.ifi_type != IFT_ETHER)
        return EPROTONOSUPPORT;
    if (ifv->ifv_p != NULL || ifv->ifv_detaching) {
        return EBUSY;
    }
    if (vlan_lookup_ifp_and_tag(p, tag) != NULL) {
        /* already a VLAN with that tag on this interface */
        return (EADDRINUSE);
    }
    ifp = ifv->ifv_ifp;
    ifv->ifv_encaplen = ETHER_VLAN_ENCAP_LEN;
    ifv->ifv_mintu = ETHERMIN;
    ifv->ifv_flags = 0;

    /*
     * If the parent supports the VLAN_MTU capability,
     * i.e. can Tx/Rx larger than ETHER_MAX_LEN frames,
     * enable it.
     */
    if (p->if_hwassist & (IF_HWASSIST_VLAN_MTU | IF_HWASSIST_VLAN_TAGGING)) {
        supports_vlan_mtu = 1;
    }
    if (p->if_nvlans == 0) {
        u_long  dltag;
        u_long  filter_id;
        int     error;

        /* attach our VLAN "interface filter" to the interface */
        error = vlan_attach_filter(p, &filter_id);
        if (error) {
            return (error);
        }

        /* attach our VLAN "protocol" to the interface */
        error = vlan_attach_protocol(p);
        if (error) {
            (void)vlan_detach_filter(filter_id);
            return (error);
        }
        ifv->ifv_filter_id = filter_id;
        ifv->ifv_filter_valid = TRUE;
#if 0
        if (supports_vlan_mtu) {
            /*
             * Enable Tx/Rx of VLAN-sized frames.
             */
            p->if_capenable |= IFCAP_VLAN_MTU;
            if (p->if_flags & IFF_UP) {
                struct ifreq ifr;
                int error;
                
                ifr.ifr_flags = p->if_flags;
                error = (*p->if_ioctl)(p, SIOCSIFFLAGS,
                                       (caddr_t) &ifr);
                if (error) {
                    if (p->if_nvlans == 0)
                        p->if_capenable &= ~IFCAP_VLAN_MTU;
                    return (error);
                }
            }
        }
#endif 0
    } else {
        struct ifvlan *         other_ifv;

        other_ifv = vlan_lookup_ifp(p);
        if (other_ifv == NULL) {
            printf("vlan: other_ifv can't be NULL\n");
            return (EINVAL);
        }
        ifv->ifv_filter_id = other_ifv->ifv_filter_id;
        ifv->ifv_filter_valid = TRUE;
    }
    p->if_nvlans++;
    if (supports_vlan_mtu) {
        ifv->ifv_mtufudge = 0;
    } else {
        /*
         * Fudge the MTU by the encapsulation size.  This
         * makes us incompatible with strictly compliant
         * 802.1Q implementations, but allows us to use
         * the feature with other NetBSD implementations,
         * which might still be useful.
         */
        ifv->ifv_mtufudge = ifv->ifv_encaplen;
    }

    ifv->ifv_p = p;
    ifp->if_mtu = p->if_mtu - ifv->ifv_mtufudge;
    /*
     * Copy only a selected subset of flags from the parent.
     * Other flags are none of our business.
     */
    ifp->if_flags |= (p->if_flags &
                      (IFF_BROADCAST | IFF_MULTICAST | IFF_SIMPLEX));
    /*
     * If the parent interface can do hardware-assisted
     * VLAN encapsulation, then propagate its hardware-
     * assisted checksumming flags.
     */
    if (p->if_hwassist & IF_HWASSIST_VLAN_TAGGING) {
        ifp->if_hwassist |= IF_HWASSIST_CSUM_FLAGS(p->if_hwassist);
    }
    /*
     * Set up our ``Ethernet address'' to reflect the underlying
     * physical interface's.
     */
    ifa1 = ifaddr_byindex(ifp->if_index);
    ifa2 = ifaddr_byindex(p->if_index);
    sdl1 = (struct sockaddr_dl *)ifa1->ifa_addr;
    sdl2 = (struct sockaddr_dl *)ifa2->ifa_addr;
    sdl1->sdl_type = IFT_ETHER;
    sdl1->sdl_alen = ETHER_ADDR_LEN;
    bcopy(LLADDR(sdl2), LLADDR(sdl1), ETHER_ADDR_LEN);
    bcopy(LLADDR(sdl2), IFP2AC(ifp)->ac_enaddr, ETHER_ADDR_LEN);

    /*
     * Configure multicast addresses that may already be
     * joined on the vlan device.
     */
    (void)vlan_setmulti(ifp);
    ifp->if_output = vlan_output;
    ifv->ifv_tag = tag;

    return 0;
}

static void
vlan_link_event(struct ifnet * ifp, struct ifnet * p)
{
    struct ifmediareq ifmr;

    /* generate a link event based on the state of the underlying interface */
    bzero(&ifmr, sizeof(ifmr));
    snprintf(ifmr.ifm_name, sizeof(ifmr.ifm_name),
             "%s%d", p->if_name, p->if_unit);
    if ((*p->if_ioctl)(p, SIOCGIFMEDIA, (caddr_t)&ifmr) == 0
        && ifmr.ifm_count > 0 && ifmr.ifm_status & IFM_AVALID) {
        u_long  event;
        
        event = (ifmr.ifm_status & IFM_ACTIVE)
            ? KEV_DL_LINK_ON : KEV_DL_LINK_OFF;
        interface_link_event(ifp, event);
    }
    return;
}

static int
vlan_unconfig(struct ifnet *ifp)
{
    struct ifaddr *ifa;
    struct sockaddr_dl *sdl;
    struct vlan_mc_entry *mc;
    struct ifvlan *ifv;
    struct ifnet *p;
    int error;

    VLAN_LOCK_ASSERT();

    ifv = ifp->if_private;

    /* Disconnect from parent. */
    p = ifv->ifv_p;
    ifv->ifv_p = NULL;

    if (p != NULL) {
        struct sockaddr_dl sdl;

        /*
         * Since the interface is being unconfigured, we need to
         * empty the list of multicast groups that we may have joined
         * while we were alive from the parent's list.
         */
        bzero((char *)&sdl, sizeof sdl);
        sdl.sdl_len = sizeof sdl;
        sdl.sdl_family = AF_LINK;
        sdl.sdl_index = p->if_index;
        sdl.sdl_type = IFT_ETHER;
        sdl.sdl_alen = ETHER_ADDR_LEN;

        while (SLIST_FIRST(&ifv->vlan_mc_listhead) != NULL) {
            mc = SLIST_FIRST(&ifv->vlan_mc_listhead);
            bcopy((char *)&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN);
            error = if_delmulti(p, (struct sockaddr *)&sdl);
            if (error) {
                printf("vlan_unconfig: if_delmulti %s failed, %d\n", 
                       ifv->ifv_name, error);
            }
            SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries);
            FREE(mc, M_VLAN);
        }
        p->if_nvlans--;
        if (p->if_nvlans == 0) {
            /* detach our VLAN "protocol" from the interface */
            if (ifv->ifv_filter_valid) {
                (void)vlan_detach_filter(ifv->ifv_filter_id);
            }
            (void)vlan_detach_protocol(p);
#if 0
            /*
             * Disable Tx/Rx of VLAN-sized frames.
             */
            p->if_capenable &= ~IFCAP_VLAN_MTU;
            if (p->if_flags & IFF_UP) {
                struct ifreq ifr;
                
                ifr.ifr_flags = p->if_flags;
                (*p->if_ioctl)(p, SIOCSIFFLAGS, (caddr_t) &ifr);
            }
#endif 0
        }
    }

    /* return to the state we were in before SETVLAN */
    ifp->if_mtu = 0;
    ifp->if_flags &= ~(IFF_BROADCAST | IFF_MULTICAST 
                       | IFF_SIMPLEX | IFF_RUNNING);
    ifv->ifv_ifp->if_hwassist = 0;
    ifv->ifv_flags = 0;
    ifv->ifv_ifp->if_output = nop_if_output;
    ifv->ifv_mtufudge = 0;
    ifv->ifv_filter_valid = FALSE;

    /* Clear our MAC address. */
    ifa = ifaddr_byindex(ifv->ifv_ifp->if_index);
    sdl = (struct sockaddr_dl *)(ifa->ifa_addr);
    sdl->sdl_type = IFT_L2VLAN;
    sdl->sdl_alen = 0;
    bzero(LLADDR(sdl), ETHER_ADDR_LEN);
    bzero(IFP2AC(ifv->ifv_ifp)->ac_enaddr, ETHER_ADDR_LEN);

    /* send a link down event */
    if (p != NULL) {
        interface_link_event(ifv->ifv_ifp, KEV_DL_LINK_OFF);
    }
    return 0;
}

static int
vlan_set_promisc(struct ifnet *ifp)
{
    struct ifvlan *ifv = ifp->if_private;
    int error = 0;

    if ((ifp->if_flags & IFF_PROMISC) != 0) {
        if ((ifv->ifv_flags & IFVF_PROMISC) == 0) {
            error = ifpromisc(ifv->ifv_p, 1);
            if (error == 0)
                ifv->ifv_flags |= IFVF_PROMISC;
        }
    } else {
        if ((ifv->ifv_flags & IFVF_PROMISC) != 0) {
            error = ifpromisc(ifv->ifv_p, 0);
            if (error == 0)
                ifv->ifv_flags &= ~IFVF_PROMISC;
        }
    }

    return (error);
}

static int
vlan_ioctl(struct ifnet *ifp, u_long cmd, void * data)
{
    struct ifaddr *ifa;
    struct ifnet *p;
    struct ifreq *ifr;
    struct ifvlan *ifv;
    struct vlanreq vlr;
    int error = 0;

    ifr = (struct ifreq *)data;
    ifa = (struct ifaddr *)data;
    ifv = (struct ifvlan *)ifp->if_private;

    switch (cmd) {
    case SIOCSIFADDR:
        ifp->if_flags |= IFF_UP;
        break;

    case SIOCGIFMEDIA:
        VLAN_LOCK();
        if (ifv->ifv_p != NULL) {
            error = (*ifv->ifv_p->if_ioctl)(ifv->ifv_p,
                                            SIOCGIFMEDIA, data);
            VLAN_UNLOCK();
            /* Limit the result to the parent's current config. */
            if (error == 0) {
                struct ifmediareq *ifmr;

                ifmr = (struct ifmediareq *) data;
                if (ifmr->ifm_count >= 1 && ifmr->ifm_ulist) {
                    ifmr->ifm_count = 1;
                    error = copyout(&ifmr->ifm_current,
                                    ifmr->ifm_ulist, 
                                    sizeof(int));
                }
            }
        } else {
            struct ifmediareq *ifmr;
            VLAN_UNLOCK();
            
            ifmr = (struct ifmediareq *) data;
            ifmr->ifm_current = 0;
            ifmr->ifm_mask = 0;
            ifmr->ifm_status = IFM_AVALID;
            ifmr->ifm_active = 0;
            ifmr->ifm_count = 1;
            if (ifmr->ifm_ulist) {
                error = copyout(&ifmr->ifm_current,
                                ifmr->ifm_ulist, 
                                sizeof(int));
            }
            error = 0;
        }
        break;

    case SIOCSIFMEDIA:
        error = EINVAL;
        break;

    case SIOCSIFMTU:
        /*
         * Set the interface MTU.
         */
        VLAN_LOCK();
        if (ifv->ifv_p != NULL) {
            if (ifr->ifr_mtu > (ifv->ifv_p->if_mtu - ifv->ifv_mtufudge)
                || ifr->ifr_mtu < (ifv->ifv_mintu - ifv->ifv_mtufudge)) {
                error = EINVAL;
            } else {
                ifp->if_mtu = ifr->ifr_mtu;
            }
        } else {
            error = EINVAL;
        }
        VLAN_UNLOCK();
        break;

    case SIOCSETVLAN:
        error = copyin(ifr->ifr_data, &vlr, sizeof(vlr));
        if (error)
            break;
        if (vlr.vlr_parent[0] == '\0') {
            VLAN_LOCK();
            vlan_unconfig(ifp);
#if 0
            if (ifp->if_flags & IFF_UP)
                if_down(ifp);
            ifp->if_flags &= ~IFF_RUNNING;
#endif 0
            VLAN_UNLOCK();
            break;
        }
        p = ifunit(vlr.vlr_parent);
        if (p == 0) {
            error = ENOENT;
            break;
        }
        /*
         * Don't let the caller set up a VLAN tag with
         * anything except VLID bits.
         */
        if (vlr.vlr_tag & ~EVL_VLID_MASK) {
            error = EINVAL;
            break;
        }
        VLAN_LOCK();
        error = vlan_config(ifv, p, vlr.vlr_tag);
        if (error) {
            VLAN_UNLOCK();
            break;
        }
        ifp->if_flags |= IFF_RUNNING;
        VLAN_UNLOCK();

        /* Update promiscuous mode, if necessary. */
        vlan_set_promisc(ifp);

        /* generate a link event */
        vlan_link_event(ifp, p);
        break;
                
    case SIOCGETVLAN:
        bzero(&vlr, sizeof vlr);
        VLAN_LOCK();
        if (ifv->ifv_p != NULL) {
            snprintf(vlr.vlr_parent, sizeof(vlr.vlr_parent),
                     "%s%d", ifv->ifv_p->if_name, 
                     ifv->ifv_p->if_unit);
            vlr.vlr_tag = ifv->ifv_tag;
        }
        VLAN_UNLOCK();
        error = copyout(&vlr, ifr->ifr_data, sizeof vlr);
        break;
                
    case SIOCSIFFLAGS:
        /*
         * For promiscuous mode, we enable promiscuous mode on
         * the parent if we need promiscuous on the VLAN interface.
         */
        if (ifv->ifv_p != NULL)
            error = vlan_set_promisc(ifp);
        break;

    case SIOCADDMULTI:
    case SIOCDELMULTI:
        error = vlan_setmulti(ifp);
        break;
    default:
        error = EOPNOTSUPP;
    }
    return error;
}

static int 
nop_if_ioctl(struct ifnet * ifp, u_long cmd, void * data)
{
    return EOPNOTSUPP;
}

static int 
nop_if_bpf(struct ifnet *ifp, int mode, bpf_callback_func * func)
{
    return ENODEV;
}

static int 
nop_if_free(struct ifnet * ifp)
{
    return 0;
}

static int 
nop_if_output(struct ifnet * ifp, struct mbuf * m)
{
    if (m != NULL) {
        m_freem_list(m);
    }
    return 0;
}

static int 
vlan_if_free(struct ifnet * ifp)
{
    struct ifvlan *ifv;

    if (ifp == NULL) {
        return 0;
    }
    ifv = (struct ifvlan *)ifp->if_private;
    if (ifv == NULL) {
        return 0;
    }
    ifp->if_private = NULL;
    dlil_if_release(ifp);
    FREE(ifv, M_VLAN);
    return 0;
}

/*
 * Function: vlan_if_filter_detach
 * Purpose:
 *   Destroy all vlan interfaces that refer to the interface
 */
static int
vlan_if_filter_detach(caddr_t cookie)
{
    struct ifnet *      ifp;
    struct ifvlan *     ifv;
    struct ifnet *      p = (struct ifnet *)cookie;

    VLAN_LOCK();
    while (TRUE) {
        ifv = vlan_lookup_ifp(p);
        if (ifv == NULL) {
            break;
        }
        if (ifv->ifv_detaching) {
            continue;
        }
        /* make sure we don't invoke vlan_detach_filter */
        ifv->ifv_filter_valid = FALSE;
        vlan_remove(ifv);
        ifp = ifv->ifv_ifp;
        VLAN_UNLOCK();
        vlan_if_detach(ifp);
        VLAN_LOCK();
    }
    VLAN_UNLOCK();
    return (0);
}

/*
 * Function: vlan_attach_filter
 * Purpose:
 *   We attach an interface filter to detect when the underlying interface
 *   goes away.  We are forced to do that because dlil does not call our
 *   protocol's dl_event function for KEV_DL_IF_DETACHING.
 */

static int
vlan_attach_filter(struct ifnet * ifp, u_long * filter_id)
{
    int                         error;
    struct dlil_if_flt_str      filt;

    bzero(&filt, sizeof(filt));
    filt.filter_detach = vlan_if_filter_detach;
    filt.cookie = (caddr_t)ifp;
    error = dlil_attach_interface_filter(ifp, &filt, filter_id, 
                                         DLIL_LAST_FILTER);
    if (error) {
        printf("vlan: dlil_attach_interface_filter(%s%d) failed, %d\n",
               ifp->if_name, ifp->if_unit, error);
    }
    return (error);
}

/*
 * Function: vlan_detach_filter
 * Purpose:
 *   Remove our interface filter.
 */
static int
vlan_detach_filter(u_long filter_id)
{
    int         error;

    error = dlil_detach_filter(filter_id);
    if (error) {
        printf("vlan: dlil_detach_filter failed, %d\n", error);
    }
    return (error);
}

/*
 * Function: vlan_proto_input
 * Purpose:
 *   This function is never called.  We aren't allowed to leave the
 *   function pointer NULL, so this function simply free's the mbuf.
 */
static int
vlan_proto_input(m, frame_header, ifp, dl_tag, sync_ok)
    struct mbuf  *m;
    char         *frame_header;
    struct ifnet *ifp;
    u_long           dl_tag;
    int          sync_ok;
{
    m_freem(m);
    return (EJUSTRETURN);
}

static struct ifnet *
find_if_name_unit(const char * if_name, int unit)
{
    struct ifnet * ifp;
    
    TAILQ_FOREACH(ifp, &ifnet, if_link) {
        if (strcmp(if_name, ifp->if_name) == 0 && unit == ifp->if_unit) {
            return (ifp);
        }
    }
    return (ifp);
}

static void
interface_link_event(struct ifnet * ifp, u_long event_code)
{
    struct {
        struct kern_event_msg   header;
        u_long                  unit;
        char                    if_name[IFNAMSIZ];
    } event;

    event.header.total_size    = sizeof(event);
    event.header.vendor_code   = KEV_VENDOR_APPLE;
    event.header.kev_class     = KEV_NETWORK_CLASS;
    event.header.kev_subclass  = KEV_DL_SUBCLASS;
    event.header.event_code    = event_code;
    event.header.event_data[0] = ifp->if_family;
    event.unit                 = (u_long) ifp->if_unit;
    strncpy(event.if_name, ifp->if_name, IFNAMSIZ);
    dlil_event(ifp, &event.header);
    return;
}

static void
parent_link_event(struct ifnet * p, u_long event_code)
{
    struct ifvlan * ifv;

    LIST_FOREACH(ifv, &ifv_list, ifv_list) {
        if (p == ifv->ifv_p) {
            interface_link_event(ifv->ifv_ifp, event_code);
        }
    }
    return;

}

/* 
 * Function: vlan_dl_event
 * Purpose:
 *   Process DLIL events that interest us.  Currently, that is
 *   just the interface UP and DOWN.  Ideally, this would also
 *   include the KEV_DL_IF_DETACH{ING} messages, which would eliminate
 *   the need for an interface filter.
 */
static int
vlan_dl_event(struct kern_event_msg * event, u_long dl_tag)
{
    struct ifnet *              p;
    struct net_event_data *     net_event;

    if (event->vendor_code != KEV_VENDOR_APPLE
        || event->kev_class != KEV_NETWORK_CLASS
        || event->kev_subclass != KEV_DL_SUBCLASS) {
        goto done;
    }
    net_event = (struct net_event_data *)(event->event_data);
    switch (event->event_code) {
    case KEV_DL_LINK_OFF:
    case KEV_DL_LINK_ON:
        p = find_if_name_unit(net_event->if_name, net_event->if_unit);
        if (p != NULL) {
            parent_link_event(p, event->event_code);
        }
        break;
#if 0
    case KEV_DL_IF_DETACHING:
    case KEV_DL_IF_DETACHED:
        /* we don't get these, unfortunately */
        break;
#endif 0
    default:
        break;
    }

 done:
    return (0);
}

/*
 * Function: vlan_attach_protocol
 * Purpose:
 *   Attach a DLIL protocol to the interface, using the ETHERTYPE_VLAN
 *   demux ether type.  We're not a real protocol, we'll never receive
 *   any packets because they're intercepted by ether_demux before 
 *   our input routine would be called.
 *
 *   The reasons for attaching a protocol to the interface are:
 *   1) add a protocol reference to the interface so that the underlying
 *      interface automatically gets marked up while we're attached
 *   2) receive link status events which we can propagate to our
 *      VLAN interfaces.
 */
static int
vlan_attach_protocol(struct ifnet *ifp)
{
    struct dlil_demux_desc      desc;
    u_long                      dl_tag;
    u_short                     en_native = ETHERTYPE_VLAN;
    int                         error;
    int                         i;
    struct dlil_proto_reg_str   reg;

    TAILQ_INIT(&reg.demux_desc_head);
    desc.type = DLIL_DESC_RAW;
    desc.variants.bitmask.proto_id_length = 0;
    desc.variants.bitmask.proto_id = 0;
    desc.variants.bitmask.proto_id_mask = 0;
    desc.native_type = (char *) &en_native;
    TAILQ_INSERT_TAIL(&reg.demux_desc_head, &desc, next);
    reg.interface_family = ifp->if_family;
    reg.unit_number      = ifp->if_unit;
    reg.input            = vlan_proto_input;
    reg.pre_output       = 0;
    reg.event            = vlan_dl_event;
    reg.offer            = 0;
    reg.ioctl            = 0;
    reg.default_proto    = 0;
    reg.protocol_family  = VLAN_PROTO_FAMILY;

    error = dlil_attach_protocol(&reg, &dl_tag);
    if (error) {
        printf("vlan_proto_attach(%s%d) dlil_attach_protocol failed, %d\n",
               ifp->if_name, ifp->if_unit, error);
    }
    return (error);
}

/*
 * Function: vlan_detach_protocol
 * Purpose:
 *   Detach our DLIL protocol from an interface
 */
static int
vlan_detach_protocol(struct ifnet *ifp)
{
    u_long      dl_tag;
    int         error;

    error = dlil_find_dltag(ifp->if_family, ifp->if_unit, 
                            VLAN_PROTO_FAMILY, &dl_tag);
    if (error) {
        printf("vlan_proto_detach(%s%d) dlil_find_dltag failed, %d\n",
               ifp->if_name, ifp->if_unit, error);
    } else {
        error = dlil_detach_protocol(dl_tag);
        if (error) {
            printf("vlan_proto_detach(%s%d) dlil_detach_protocol failed, %d\n",
                   ifp->if_name, ifp->if_unit, error);
        }
    }
    return (error);
}

/*
 * DLIL interface family functions
 *   We use the ethernet dlil functions, since that's all we support.
 *   If we wanted to handle multiple LAN types (tokenring, etc.), we'd
 *   call the appropriate routines for that LAN type instead of hard-coding
 *   ethernet.
 */
extern int ether_add_if(struct ifnet *ifp);
extern int ether_del_if(struct ifnet *ifp);
extern int ether_init_if(struct ifnet *ifp);
extern int ether_add_proto(struct ddesc_head_str *desc_head, 
                           struct if_proto *proto, u_long dl_tag);
extern int ether_del_proto(struct if_proto *proto, u_long dl_tag);
extern int ether_ifmod_ioctl(struct ifnet *ifp, u_long command,
                             caddr_t data);
extern int ether_del_proto(struct if_proto *proto, u_long dl_tag);
extern int ether_add_proto(struct ddesc_head_str *desc_head, struct if_proto *proto, u_long dl_tag);

extern int ether_attach_inet(struct ifnet *ifp, u_long *dl_tag);
extern int ether_detach_inet(struct ifnet *ifp, u_long dl_tag);
extern int ether_attach_inet6(struct ifnet *ifp, u_long *dl_tag);
extern int ether_detach_inet6(struct ifnet *ifp, u_long dl_tag);

static int
vlan_attach_inet(struct ifnet *ifp, u_long *dl_tag)
{
    return (ether_attach_inet(ifp, dl_tag));
}

static int
vlan_detach_inet(struct ifnet *ifp, u_long dl_tag)
{
    return (ether_detach_inet(ifp, dl_tag));
}

static int
vlan_attach_inet6(struct ifnet *ifp, u_long *dl_tag)
{
    return (ether_attach_inet6(ifp, dl_tag));
}

static int
vlan_detach_inet6(struct ifnet *ifp, u_long dl_tag)
{
    return (ether_detach_inet6(ifp, dl_tag));
}

static int
vlan_add_if(struct ifnet *ifp)
{
    return (ether_add_if(ifp));
}

static int
vlan_del_if(struct ifnet *ifp)
{
    return (ether_del_if(ifp));
}

static int
vlan_init_if(struct ifnet *ifp)
{
    return (0);
}

static int
vlan_shutdown()
{
    return 0;
}

__private_extern__ int
vlan_family_init()
{
    int  i, error=0;
    struct dlil_ifmod_reg_str  ifmod_reg;
    struct dlil_protomod_reg_str vlan_protoreg;

#if 0
    /* VLAN family is built-in, called from ether_family_init */
    thread_funnel_switch(KERNEL_FUNNEL, NETWORK_FUNNEL);
#endif 0

    bzero(&ifmod_reg, sizeof(ifmod_reg));
    ifmod_reg.add_if = vlan_add_if;
    ifmod_reg.del_if = vlan_del_if;
    ifmod_reg.init_if = vlan_init_if;
    ifmod_reg.add_proto = ether_add_proto;
    ifmod_reg.del_proto = ether_del_proto;
    ifmod_reg.ifmod_ioctl = ether_ifmod_ioctl;
    ifmod_reg.shutdown    = vlan_shutdown;

    if (dlil_reg_if_modules(APPLE_IF_FAM_VLAN, &ifmod_reg)) {
        printf("WARNING: vlan_family_init -- "
               "Can't register if family modules\n");
        error = EIO;
        goto done;
    }

    /* Register protocol registration functions */
    bzero(&vlan_protoreg, sizeof(vlan_protoreg));
    vlan_protoreg.attach_proto = vlan_attach_inet;
    vlan_protoreg.detach_proto = vlan_detach_inet;
        
    if (error = dlil_reg_proto_module(PF_INET, APPLE_IF_FAM_VLAN, 
                                      &vlan_protoreg) != 0) {
        kprintf("dlil_reg_proto_module failed for AF_INET6 error=%d\n",
                error);
        goto done;
    }
    vlan_protoreg.attach_proto = vlan_attach_inet6;
    vlan_protoreg.detach_proto = vlan_detach_inet6;
        
    if (error = dlil_reg_proto_module(PF_INET6, APPLE_IF_FAM_VLAN, 
                                      &vlan_protoreg) != 0) {
        kprintf("dlil_reg_proto_module failed for AF_INET6 error=%d\n",
                error);
        goto done;
    }
    vlan_clone_attach();

 done:
#if 0
    thread_funnel_switch(NETWORK_FUNNEL, KERNEL_FUNNEL);
#endif 0
    return (error);
}